Nu Orionis (ν Orionis) is a binary star[11] system in the northeastern part of the constellation Orion. It should not be confused with the variable star NU Orionis.[12] Nu Orionis has an apparent visual magnitude of 4.42,[2] which is bright enough to be seen with the naked eye. Based upon an annual parallax shift of 0.00632 arcseconds,[1] the distance to this system is roughly 520 light years.
  | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Orion |
| Right ascension | 06h 07m 34.32588s[1] |
| Declination | +14° 46′ 06.5061″[1] |
| Apparent magnitude (V) | 4.42[2] |
| Characteristics | |
| Spectral type | B3 V[3] or B3 IV[4] |
| U−B color index | −0.67[2] |
| B−V color index | −0.18[2] |
| Astrometry | |
| Radial velocity (Rv) | +24.1[5] km/s |
| Proper motion (μ) | RA: +6.78[1] mas/yr Dec.: −20.23[1] mas/yr |
| Parallax (π) | 6.32 ± 0.33 mas[1] |
| Distance | 520 ± 30 ly (158 ± 8 pc) |
| Orbit[6] | |
| Period (P) | 131.211 d |
| Eccentricity (e) | 0.64 |
| Periastron epoch (T) | 2436475.852 JD |
| Argument of periastron (ω) (secondary) | 6.6° |
| Semi-amplitude (K1) (primary) | 33.3 km/s |
| Details | |
| ν Ori A | |
| Mass | 6.7±0.1[4] M☉ |
| Radius | 4.3[7] R☉ |
| Luminosity | 1,965[3] L☉ |
| Surface gravity (log g) | 4.06[8] cgs |
| Temperature | 17,880[8] K |
| Metallicity [Fe/H] | −0.05[8] dex |
| Rotational velocity (v sin i) | 30[9] km/s |
| Age | 26.3±5.3[4] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is a single-lined spectroscopic binary system,[9] which means that only the absorption line features of one of the components can be distinguished. The components orbit each other with a period of 131.2 days and an eccentricity of 0.64.[6] Depending on the source, the primary is either a B-type main sequence star with a stellar classification of B3 V,[3] or a more evolved B-type subgiant star of class B3 IV.[4] It has an angular diameter of 0.251 mas,[13] which, at the estimated distance of this system, yields a physical size of about 4.3 times the radius of the Sun.[7] The mass is 6.7[4] times that of the Sun and it shines with 1,965[3] times the solar luminosity from its outer atmosphere at an effective temperature of 17,880 K.[8]
References
edit- ^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
- ^ a b c d Crawford, D. L.; et al. (1971), "Four-color, H-beta, and UBV photometry for bright B-type stars in the northern hemisphere", The Astronomical Journal, 76: 1058, Bibcode:1971AJ.....76.1058C, doi:10.1086/111220.
- ^ a b c d Hohle, M. M.; et al. (April 2010), "Masses and luminosities of O- and B-type stars and red supergiants", Astronomische Nachrichten, 331 (4): 349–360, arXiv:1003.2335, Bibcode:2010AN....331..349H, doi:10.1002/asna.200911355, S2CID 111387483.
- ^ a b c d e Tetzlaff, N.; et al. (2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society, 410 (1): 190–200, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x, S2CID 118629873.
- ^ Evans, D. S. (June 20–24, 1966), "The Revision of the General Catalogue of Radial Velocities", in Batten, Alan Henry; Heard, John Frederick (eds.), Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, vol. 30, University of Toronto: International Astronomical Union, p. 57, Bibcode:1967IAUS...30...57E.
- ^ a b Pourbaix, D.; et al. (2004), "SB9: The ninth catalogue of spectroscopic binary orbits", Astronomy and Astrophysics, 424 (2): 727–732, arXiv:astro-ph/0406573, Bibcode:2004A&A...424..727P, doi:10.1051/0004-6361:20041213, S2CID 119387088.
- ^ a b Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, vol. 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1.. The radius (R*) is given by:
- ^ a b c d Gies, Douglas R.; Lambert, David L. (March 1992), "Carbon, nitrogen, and oxygen abundances in early B-type stars", Astrophysical Journal, Part 1, 387: 673–700, Bibcode:1992ApJ...387..673G, doi:10.1086/171116.
- ^ a b Abt, Helmut A.; et al. (July 2002), "Rotational Velocities of B Stars", The Astrophysical Journal, 573 (1): 359–365, Bibcode:2002ApJ...573..359A, doi:10.1086/340590.
- ^ "nu. Ori". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2016-11-03.
- ^ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
- ^ Marett-Crosby, Michael (2013), Twenty-Five Astronomical Observations That Changed the World: And How To Make Them Yourself, The Patrick Moore Practical Astronomy Series, Springer Science & Business Media, p. 93, ISBN 978-1461468004.
- ^ Zorec, J.; et al. (July 2009), "Fundamental parameters of B supergiants from the BCD system. I. Calibration of the (λ_1, D) parameters into Teff", Astronomy and Astrophysics, 501 (1): 297–320, arXiv:0903.5134, Bibcode:2009A&A...501..297Z, doi:10.1051/0004-6361/200811147, S2CID 14969137.
